feat(auth): 新增接口签名校验与退出登录功能

src/main/java/com/yolo/keyborad/utils/SignUtils.java

@@ -0,0 +1,74 @@
+    package com.yolo.keyborad.utils;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.net.URLEncoder;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.TreeMap;
+
+public class SignUtils {
+
+    private static final String HMAC_SHA256 = "HmacSHA256";
+
+    /**
+     * 生成签名
+     * @param params 参与签名的参数（不含 sign 本身）
+     * @param secret 密钥
+     */
+    public static String sign(Map<String, String> params, String secret) {
+        // 1. 过滤掉空值和 sign 本身
+        Map<String, String> filtered = params.entrySet().stream()
+                .filter(e -> e.getValue() != null && !"sign".equalsIgnoreCase(e.getKey()))
+                .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        Map.Entry::getValue
+                ));
+
+        // 2. 按 key 字典序排序
+        Map<String, String> sorted = new TreeMap<>(filtered);
+
+        // 3. 拼接成 key=value&key2=value2...&secret=xxx
+        StringBuilder sb = new StringBuilder();
+        sorted.forEach((k, v) -> {
+            if (sb.length() > 0) {
+                sb.append("&");
+            }
+            sb.append(k).append("=").append(urlEncode(v));
+        });
+        sb.append("&secret=").append(urlEncode(secret));
+
+        String data = sb.toString();
+        return hmacSha256(data, secret);
+    }
+
+    private static String hmacSha256(String data, String secret) {
+        try {
+            Mac mac = Mac.getInstance(HMAC_SHA256);
+            SecretKeySpec secretKey = new SecretKeySpec(secret.getBytes(StandardCharsets.UTF_8), HMAC_SHA256);
+            mac.init(secretKey);
+            byte[] bytes = mac.doFinal(data.getBytes(StandardCharsets.UTF_8));
+            // 转十六进制小写
+            StringBuilder sb = new StringBuilder();
+            for (byte b : bytes) {
+                String hex = Integer.toHexString(b & 0xff);
+                if (hex.length() == 1) {
+                    sb.append("0");
+                }
+                sb.append(hex);
+            }
+            return sb.toString();
+        } catch (Exception e) {
+            throw new RuntimeException("Sign error", e);
+        }
+    }
+
+    private static String urlEncode(String str) {
+        try {
+            return URLEncoder.encode(str, StandardCharsets.UTF_8);
+        } catch (Exception e) {
+            return str;
+        }
+    }
+}